Snow plow frame

ABSTRACT

A snow plow supporting frame mounted on a vehicle in any convenient manner. The frame has a pair of pivot brackets on which the plow is mounted so that the plow can pivot on a horizontal axis transverse of the vehicle upon striking an obstacle. Air bags are provided to cushion the swiveling action, the air bags being provided with safety valves and also with a resupply air source.

United States Patent 11 1 Poirier, Sr. et al.

[ SNOW PLOW FRAME [76] inventors: Real J. Poirier, Sn; Real J. Poirier,

In, both of 5 Bridges Rd., Brimfield, Mass. 01010 [22] Filed: Oct. 9,1973 [21] Appl. No.: 404,593

[52] US. Cl. 37/42 R; 172/801; 293/71 P [51] Int. Cl A0lb 61/04 [58]Field of Search 37/42 R, 42 VL; 280/481; 293/71 P; 172/276, 801

[56] References Cited UNITED STATES PATENTS 1,833,859 11/1931 Robinsonet al. 37/42 VL 2,144,357 1/1939 Booharin 293/71 P 2,643,470 6/1953Kaeser 37/42 R 2,775,830 1/1957 Kenyon 37/42 R 2,841,894 7/1958 Valois37/42 R 3,022,587 2/1962 Greeley 280/481 X 3,238,647 2/1966 Hall et37/42 VL 1451 May 20, 1975 3,332,562 7/1967 Kokott 280/481 x 3,650,0543/1972 i-lanson........ 37/42 v1. 3,689,054 9/1972 0611113110 293/71 13,808,? 14 5/1974 Reissinger 6! a1. 37/42 VL FOREIGN PATENTS 0RAPPLICATIONS 471,288 5/1969 Switzerland 37/42 R 1,425,809 3/1965 France280/481 Primary Examiner-E. l-l. Eickhoit Attorney, Agent, orFirm-Charles R. Pay

[5 7] ABSTRACT 8 Claims, 4 Drawing Figures WJENTED M29195 SHEET 2 OF 2FIG. 2

FIG.4

SNOW PLOW FRAME BACKGROUND OF THE INVENTION Conventional snow plows areusually mounted to yield under pressure. the yielding action beingresisted by springs. Most spring mounts cause the plow to pivotforwardly and this usually results in a great deal of damage to the plowwhere obstructions are encountered. resulting in a rough edge and dentsin the blade. It is the object of the present invention to provide apivotal action of the plow so that the blade thereof yields or retractsagainst the action of a new and improved air bag construction, resultingin better automatic control of the plow when obstructions are hit and inless damage to the blade.

SUMMARY OF THE INVENTION A rigid frame which may be of conventionalconstruction is applied to a vehicle as usual in a vertical relation. Atthe low end of the frame there are provided plow support brackets whichcan pivot on a horizontal axis transverse of the vehicle. The plow ismounted on these brackets and the usual plow lifting mechanism etc.. canalso be used.

An air bag construction is set to resist the rearward pivoting of thebracket but the air bags are set so that they allow the pivot action totake place when an obstruction is encountered, but when the obstructionis removed. the air bags move the plow back to its original plowingoperational position.

The effect of this is that when an obstruction is hit. force istransmitted through the plow frame to the pivoted brackets which thenpivot i.c., to the rear. This has the effect of allowing the plow toswing to the rear. retracting or yielding. The plow blade is thereforeenabled to retract under conditions of hitting an obstructionv This inturn results in less damage to the plow blade as compared withconventional types of plow blades which are mounted for spring action topivot in the opposite direction when the lower edge or working edge atroad level strikes an obstruction.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a view in side elevationillustrating the invention'.

FIG. 2 is a front view of a plow frame; and FIG. 3 is a plan view of theair bag construction.

PREFERRED EMBODIMENT OF THE INVENTION A frame of any convenientdescription, such as those which are used in the prior art. is indicatedat I and this is mounted in any way desired to the truck chassis whichis shown at 12. This frame may have the usual plow lifter 14, I6, etc..if desired.

At the lower end of frame II] it is provided with a pair of verticallegs 20. and conveniently pivoted thereon by pins or bolts 22. 22 are apair of brackets generally indicated at 24. 24. Brackets 24 extendforwardly and are provided with a pair of apertures 26, 26 for thereception of pins holding the plow frame 28. the plow blade being shownat 30. It is to be understood that the plow and the plow frame 28 may beof any description but of course it should be liftable as by the lifterstruc ture l4, l6 pivoting with the frame 28.

The brackets 24, 24 can pivot about their pivot pins 5 22, 22 to thedotted line position in FIG. I, in which case of course the plow blade30 as a whole will retract and therefore when an obstruction isencountered at the road level the plow blade 30 will not be damaged toany extent because it retracts and does not resist the obstruction. asdoes the usual plow. which tends to pivot over towards the obstruction.

Brackets 24, 24 are mounted on a crossbeam 32 each having a rearwardlyextending portion carrying pins 34 pivoting the air bag supportstructure 36 which in turn is pivoted at 38 to a cross-support 40attached to the front axle or other part of the vehicle. As the brackets24 turn counter clockwise. FIG. 1, they cause pressure plates 40 tostart to compress the air bags 42 and the structure 36 tends to pivotclockwise. When the obstacle is removed or the plow lift over it. theair bags bring the plow back to operating positionv Frame 36 carries thetelescoping guide member 44 which is pivoted at 46 to the beam 32 whichconnects brackets 24.

The air bags are provided with a pressure release valve 48 which in turnis connected as at 50 to a source of air under pressure not shown sothat the air bags absorb the rearward motion of the brackets 24. 24 andreturn the plow to normal operating position holding it there in normaloperation for plowing except when an obstruction is hit.

We claim:

I. A snow plow and a snow plow frame for a vehicle. comprising a bracketpivoted on the frame. means mounting the snow plow on the pivotedbracket. the pivot axis of said bracket being horilontal and transverseof vehicle. direction and fielding. resilient air bag means resistingmotion of the bracket in a rearward direction under impact from anobstruction encountered by the plow. the resilient means yielding toallow the plow to relatively yield from the obstruction.

2. The device of claim I including a support for said air bag means,said support being mounted on the vehicle on which the plow is mounted.

3. The device of claim 2 wherein said frame is pivoted with respect tothe vehicle and with respect to the brackets.

4. The device of claim I including a relief valve for said air bagmeans.

5. The device of claim 4 including a source of air under pressure forreplenishing said air bag means in the event of loss of pressure throughrelief the release valve.

6. The device of claim 1 including a pressure plate in contact with theair bag means. the bracket being connected to the pressure plate.

7. The device of claim I wherein the point of attachment of the plow tothe bracket is below the pivot axis of the bracket.

8. The device of claim 2 wherein the air bag support is pivoted relativeto the vehicle.

1. A snow plow and a snow plow frame for a vehicle, comprising a bracketpivoted on the frame, means mounting the snow plow on the pivotedbracket, the pivot axis of said bracket being horizontal and transverseof vehicle, direction and fielding, resilient air bag means resistingmotion of the bracket in a rearward direction under impact from anobstruction encountered by the plow, the resilient means yielding toallow the plow to relatively yield from the obstruction.
 2. The deviceof claim 1 including a support for said air bag means, said supportbeing mounted on the vehicle on which the plow is mounted.
 3. The deviceof claim 2 wherein said frame is pivoted with respect to the vehicle andwith respect to the brackets.
 4. The device of claim 1 including arelief valve for said air bag means.
 5. The device of claim 4 includinga source of air under pressure for replenishing said air bag means inthe event of loss of pressure through relief the release valve.
 6. Thedevice of claim 1 including a pressure plate in contact with the air bagmeans, the bracket being connected to the pressure plate.
 7. The deviceof claim 1 wherein the point of attachment of the plow to the bracket isbelow the pivot axis of the bracket.
 8. The device of claim 2 whereinthe air bag support is pivoted relative to the vehicle.